Ultra-fine particles or nanoparticles (particles having an average diameter of 200 nanometers or less) are believed to be useful in the fabrication of micro-electronic devices. Alivisatos et al., in U.S. Pat. No. 5,262,357, describe a method for making semi-conductor nanoparticles from semi-conductor precursors. Alivisatos et al. describe using these semi-conductor nanoparticles to make continuous semi-conductor films. Because the semiconductor nanoparticles exhibit significantly lower melting temperature than bulk materials, a layer of the semi-conductor nanoparticles can be deposited on a substrate and annealed at relatively low temperatures, whereby the nanoparticles melt to form a continuous film.
One of the goals for nano-technology is to develop techniques and materials that will allow for the fabrication of micro devices on a variety of substrates using selective deposition, printing and/or imaging technologies. These selective deposition, printing and/or imaging technologies can utilize nanoparticles, or inks comprising nanoparticles, to fabricate device layers and structures in micro-devices.
There have been recent efforts to make metal-based solutions which can be used to make conductive device layers in the fabrication of micro-electronic devices. For example, Kydd in U.S. Pat. No. 5,882,722 describes a method of forming conductive layers from a suspension of mixtures of a metal powder and an organo-metallic compound dispensed in an organic solvent. The suspension is deposited onto a substrate to form a layer. The layer of the suspension is then cured to remove solvents and surfactants and decomposed the mixture of the metal powder and the organo-metallic compound to form the conductive layer.
Nanoparticle technologies provide alternative methods to laborious and expensive lithographic techniques for the fabrication of micro-devices and/or methods. Therefore, there is a continued need to develop new methods for making nanoparticles and new methods for using the nanoparticles in the fabrication of micro-devices that can reduce the number of mask and etch steps required during the fabrication of the micro-devices.